Steam heating



July 10, 1934. I E, BURRELL 1,965,823

STEAM HEATING Filed June 9, 1932 5 Sheets-Sheet 1 w s l 3 w C n l i i i! 1 i I:` N l Ir l...-...JL

W) $4 N l L a WATER I Evel.

July 10, 1934, E BURRLL 1,965,823

STEAM HEATING y Filed June 9, 1932 5 Sheets-Sheet 2 VVATER LEVEL:

. Inl/6222371 E7/S Barre/ July 1o, 1934. E, BURRELL 1,965,823

STEAM HEATING Filed June 9, 1932 5 Sheets-Sheet 3 CURRENT PQESURSTAT WATER LEVEL July 10, 1934. E BURRELL 1,965,823

' STEAM HEATING Filed June 9, 1932 5 Sheets-Sheet 4 WATER LEVEL.

July 10, 1934. E. BURRELL.

STEAM HEATING Filed June 9, 1952 5 Sheets-Sheet 5 Patented July 10, 1934 UNITED STATES 'STEAM HEATING Ellis Burrell, Chicago, lll., assignor to Evenaire Regulator Company, tion of Illinois Chicago, Ill., a corpora- Application June 9, 1932, Serial No. 616,280

3 Claims.

'Ihis invention relates to steam heating systems and more particularly to an arrangement of control devices therefor, whereby these devices are successively in action to bring about, at predetermined intervals, a pressure condition Within the system, with air trapped in the radiators and released therefrom according to the heat delivery requirement at the different radiators. The pressure condition is followed by a fall in .pressure to less than atmospheric pressure and by replenishing the air in the system, before a successive rise in steam pressure. In this manner the heating system may be controlled and cause the delivery of heat from various radiators to correspond with the heating requirements at dif ferent locations in the building, in accordance with changes in outside temperature conditions and heat losses from the building.

It is an object of the invention to provide in a gravity circulating steam. heating system means for causing adrop in pressure therein at regular intervals, to below atmospheric pressure, and admit air to the system for the purpose of permitting control of heat delivery from the system. It is also an object of the invention'to provide for steam pressure at regular intervals alternately with an air intaking condition of the system. A further purpose of the invention is to provide a steam heating system which will permit of dispensing with equipment such as the customary radiator control valves and air inlet means at the lradiators which are for the purpose of permitting condensate to drain back to the boiler in one-pipe systems. A further purpose of the invention is to provide an improved air inlet means remote from the radiators, and an improved device for lreleasing air at the radiators according to the extent it is desired to have the radiators lled with steam;

These objects are accomplished by heating systems as illustrated in the accompanying drawings,

Figure 1 diagrammatically illustrates the invention as applied to an intermittently hand red boiler in a steam heating system, which may be operated so that the steam supplied'to the radi-A ators and the return of the condensate' from the radiators is through one conduit, or separate conduits may be. used for the supply and return. l

In either case; the circulation is by'grjavity.

Fi'g. 2 shows a system similar to that illustrated by Fig. 1, except as modified to bring about intermittent supply of steam, although the boiler is kept at steady pressure.

Fig. 3 is a diagram showing the system as arranged in connection with a boiler which is heated by an intermittently operated oil burner.

Fig. 4 diagrammatically illustrates the system in connection with an automatically stoked boiler.

Fig. 5 is an enlarged sectional detail showing' the air inlet valve.

Fig. 6 is an end view of the valve shown in Fig. 5.

Fig. 7 isv an enlarged front view, with the cover omitted, of the thermostatic device for releasing air from the radiators according to a lowering of room temperature.

Fig. 8 is a side view ofthe regulator shown by Fig. 7.

Fig. 9 is a sectional detail taken on thel line 7o 9-9 of Fig. 8, to show the arrangement of a check Valve for preventing air from entering the radiator through the air outlet port of the regulator.

The improvements herein described relate to the use of air in steamheating systems in which `the condensate water is generally returned -to the boiler by gravity, and which are often referred to asone-pipe systems, although a separate return pipe may be provided for without changing the character of the system in so far as thepresent improvements are applicable thereto. In such a system of steam heating, the steam is supplied at a pressure above that of atmosphere, and the water condensing in the radiators returns to the boiler by gravity.

In order to insure proper draining of the radiator, it is generally necessary to leave the steam inlet valve of the radiator open. The radiator inlet valves are not necessary in the arrangement herein disclosed, and the quantity of steam entering a radiator is not regulated by the steam valve, but is regulated by the release of air from the radiator, thus making room for the entering steam. 95 In vthe present system, regulation of the heat delivery of different radiators is effected by releasing more or less air from such radiators, and replenishing the air so released. The system is allowed to cool at intervals and take in more air. The air relief valves at the radiators depend for operation upon room temperature changes. The boiler pressure may be maintained constant, or is raised 'and lowered at-defnite intervals, but the feed of steam to the system is controlled by the operation of a timing mechanism which insures shutting oi the steam supply at intervals and allowing thepressure to drop below atmospheric pressure, at which time air is supplied to the system, and then upon a rise in pressure the 11@ therein, depending upon room temperature conditions.

The drawings illustrate various means for interrupting the steam supply. Provision is also made for changing the operation of the system when the lires are banked for the night, so that it may continue to supply steam to the radiators at less than atmospheric pressure.

Referring to the arrangement illustrated by Figure 1, the `boiler 1 is shown provided with a customary check damper 2, draft damper Elv and firing door damper 4 under the control of a lever 5. This lever is shifted to control the setting of the dampers to increase ordecrease the rate of combustion by a pressure regulator 6, or an electrically heated expansion motor 7, which is in a circuit 8, under Vthe control of a clock actuated switch 9.

Cable connections 10 and 10 are made between the lever 5 and the dampers 2, 3 and 4. When the lever is shifted in one direction, the dampers are adjusted to decrease the normal rate of combustion and permit the steam-pressure to drop to zero. This occurs at intervals several times a day, and when the radiators, which are indicated at 11, cool suicently to cause av partial vacuum in the system,.an air inlet valve 12 in the steam supply main 13 opens and allows the system to ll with air above the Water level therein.

When the switch 9 opens under the action of the clock, the rate of combustion in the boiler is increased-as the dampers are restored to normal condition. As the steam pressure rises, the air in the supply main 13 is released by the customary air venting means 14, with which such supply lines are generally equipped. but the airpocketed in the radiators is either retained therein or released therefrom by means of individual relief valves or regulators 15, depending upon room temperatures where these radiators are located. This regulator is illustrated by-Figures '7, 8 and 9. The outlet port 16 of the regulator is formed to provide a seat fora valve 17 at the end of the thermostatic element 18, which is subjectA to the temperature of air passing upwardly at the end of the radiator. The regulator is insulated from theradiator by a spacing element 19 of bakelite. which carries a nipple by which .the regulator is attached tothe radiator.

The thermostatic strip is fulcrumed'on a knifeedge. pin 21, carried by a post 22. The thermostatic element is held against its fulcrum by a spring 23,V and its angular setting for operation at some predetermined temperature is made by eccentric 24, which may be rotated by setting lever 25. The eccentric bears against a screw'26 passing threugh the lower end .of the thermostatic element.'

The outlet port 16 communicates with a chamber 27 formed in the body 28 of the regulator.

A 'I'he chamber 27 communicates with a hollow Y ber 27.

If the pressure within the radiator is less than atmospheric pressure, the disc 32 will seat over the passageway 30, but is lifted from its seat when the air pressure within the radiator exceeds the atmospheric pressure on the opposite side of the disc. The hollow part 29 of the regulator body 28 carries oiled metallic wool for ltering the air passing through the regulator, and thus stops impurities from lodging upon the valve seats.

Figure 2 illustrates the control system as modified for application to gravity steam heating systems Where the steam is supplied at some constant pressure. In such case, in order to operate the system to bring about alternate pressure and vacuum conditions, it is necessary to shut oi and open up the steam supply line at intervals. This is done by means of an electrically operated shutolf valve 33, the circuit of which is controlled by a clock or manually operated switch 34. Otherwise,

the operation of the arrangement shown by Fig.

2 is the same as that shown by Fig. l, the regulators 15 releasing air from the radiators to the extent that heat is required at the location of the radiators, and during the interval that steam pressure is maintained.

When the steam supply line is shut olf and the .radiators cooled to a partial vacuum condition, the system is recharged with air through the automatic inlet valve 12.- The air vent 14 in the radiator supply conduit 35 is of the usual thermostatic type which opens on air pressure but closes when subjected tothe heat of the system, or vacuum.

The arrangement shown by Fig. 2 is applicable in zoning systems, Where a constantv supply of steam is available for diiferent zones.

Figure 3 is another variation illustrating the time-actuated means 36 for bringing about a1- ternate pressure and vacuum conditions.

Figure 4 also shows a modied means for bringing about the desired repeated cycles of operation whereby alternate pressure and vacuum conditions occur in the system when the boiler is red by an automatic stoker. The stokei is indicated diagrammatically at 37. is driven by an electric motor in'a. circuit 38 controlled by a clock-actuated switch 39.

The furnace damper 40 is adjusted by a heat motor 41, the coil of which is in a circuit 42 also under the control of the clock-actuated switch 39. Otherwise the system operates the same as those previously described, the air intake being through a valve 12 and the release of 'air from the radiators by the regulators 15 when the room temperature drops below the point at which the regulators are set.

The air inlet valve, illustrated by Figures 5 and 6, is normally closed when pressure conditions exist in the system, as the valve disc 45 is then forced against its seat 46. The disc 45 is preferably glass to provide a hard non-wearing and non-corroding surface for engagingthe seat.

The valve disc 45 is Supported by a bent arm 49 pivoted to the body of the valve on pin 50. The spring 47 bears between the disc 45 and a shoulder 51 on arm 49 and the disc can move relatively to the arm but this arm is countery l weighted at 52 to resiliently support the disc.

The screw head 53 on the end of arm 49 serves to hold the spring 47 under compression.

iWhen the difference in pressure on opposite sides of the disc causes the valve to'open or close, the arm 49 rocks on its fulcrum 50, and the angular setting of the disc, with reference to -the` seat, changes but upon the 'seating action the spring allows the disc to adjust itself to the seat. At night time when the steam pressure may be kept low throughout the night, and it is desired to prevent the opening'of valve 45, it may be Y locked to its seat by eccentric 54 operated by 150' a central point there is lever 55. The *arm* 49 is cut out at 56 so as to be clear of the eccentric in one position of lever 55. When the disc is locked to its seat, the heating system may be operated as a vapor system, no air being admitted ,thereto and the radiators are illled with the low pressure steam.

In `.he operation of any of the arrangements illustrated by the'diagrams, lwhen the rires are' checked or the steam is cut off after definite time intervals, the condensing steam in the radiators causes the pressure in thesystem to fall below atmospheric pressure at-which time the automatic -air intake valve opens and floods' the sys tem with air. Then when the clock-control switch, indicated at 9 Figure 1, at 36 Figure 3, and at 39 Figure 4, closes thus causing steam pressure to be built up in the system, the air in the main steam heat lines is vented by the air vents 14 until these devices are heated by steam temperature when they close. The remaining air, which is pocketed in the radiators and the conduits leading thereto, is slowly vented through the regulators 15 until the rooms in which the radiators are located reach the temperature at which the regulators are set for closing. In this manner the radiators are con` trolled to maintain a rate of heat delivery which is not in excess of that required for maintaining a desired room temperature'.

In some heating systems of this general class it has been the customn'to admit air thereto at each radiator, having the effect of quickly cooling the radiator. In the present arrangement a single air inlet valve is employed for a group of radiators and it is located at or near the boiler. The air is warmed in its passage through the conduits leading to the radiators and it is thus possible to conserve' the heat in the radiators, and the arrangement also makes it possible to have a central control convenient for either manual or automatic operation. l

The arrangementhas the further advantage in-that by admitting air to the system only at only one device requiring adjustment for preventing any air from entering the system for example at night when the pressure is low and it is desired to cause the continuous circulation of steam or vapor.

In large buildings where the system is divided into plurality of independent zones at least one air inlet valve is required for each zone.

When the fires are banked for the night, it is desirable in many cases to supply heat at a low temperature to all radiators and to prevent air from entering the system. By having a single air inlet valve 12 for the system and located near the boiler, a `convenient means is afforded for preventing ingress of air and for this reason the valve 12, Figure 5, is provided with the shutott lock element 55. The fire door damper 4, Figure -1, is unhooked so that it may remain closed-during the night and thus conserve heat by preventing a draft over thefire. The clock operated switch controlling thel heat motor circuit remains closed.- These devices, being standard articles, lare known as program clocks, the switch opening means being effective only during the day.

I claim: p

l. In a system of temperature controlfor steam heating systems of the gravity return type, a steam heating system comprising a source of steam supply, a plurality of radiators and conduit connections between said source f supply and radiators, each of' said radiators being equipped with an air release valve and means which prevents the'entrance of air into the radiators through said valve, thermostatic controlling the operation of said valves, to open the valves upon ,lowering of temperatures to predetermined points, an air inlet valve mounted on the conduit connections between steam supply and the radiators, said air inlet valve vbeing constructed to open by atmospheric pressure and admit air lto the system only when the pressure therein drops below that of the atmos- Kphere, and means for periodically reducing the steam pressure in the heating system below -atmospheric pressure.

2. In a system oi temperature control for a steam heating system of the gravity return type, a steam heating system comprising a source of steam supply, a plurality of radiators and conduit connections between said source of supply the source. of`

means -for and radiators, each of said radiators being equipped with an air release valve and a check which prevents the entrance of air into the radiators through said valve-,fthermostatic means for controlling the operation the valves upon determined points, an air inlet valve mounted on the cond 't connections between the source of steam supply and the radiators constructed to automatically admit air to the system when the of said valves, to open f lowering of temperatures to prepressure therein drops below atmospheric pressure, means for periodically reducing the steam pressure in the heating system below atmospheric pressure, and means opening of said air intake valve.

- 3. In a system of temperature control a steam heating system of the gravity return type, a steam heating system comprising a source of steam supply, a plurality of radiators and conduit connections between said source of supply and radiators,

for preventing the each of said radiators being equipped with anair release valve, thermostatic means for controlling the operation of said valves to open the valves upon the lowering of the temperatures to prede--4 termined points, said air release valves being equipped with therethrough when-the pressure within the radi'- ators is less than atmospheric pressure, an air niiet valve mounted on the conduit connections between the source of steam supply and the radiators constructed to automatically admit air to the system when the pressure therein drops below atmospheric pressure, and means for periodically reducing the steam pressure in the heating system below atmospheric pressure.v

EILISBURREIL.

checks for preventing inflow of air alsv 

